Roman Calendar

The calendar system used in ancient Rome, combining lunar origins with a civil year shaped by political authority and periodic reform.

Roman calendar reform: Changes to Rome’s calendar that altered its structure, timing, or administration. Reforms addressed the growing mismatch between the civil year and the seasons.
Romulus: The legendary founder and first king of Rome in Roman tradition. Ancient accounts attributed an early ten-month calendar to Rome’s legendary founder.
Roman consuls: The two annually elected chief magistrates of the Roman Republic. Romans commonly identified a year by naming its serving consuls.
Roman dating conventions: The Roman methods for naming days, months, and years. Roman date names and backward counting shaped later historical descriptions of Roman time.
Intercalation: The insertion of extra days or months into a calendar to align its year with an astronomical cycle. Roman officials inserted an extra month to correct seasonal drift.
Numa Pompilius: The second king of Rome in Roman tradition, credited with establishing religious institutions. Roman tradition credited Numa with adding January and February to the calendar.
Roman festivals: Public religious celebrations held at prescribed times in ancient Rome. The calendar scheduled festivals and marked days set aside for worship.
Anno Domini: A system for numbering years from the traditionally calculated year of Jesus Christ’s birth. This later European era was applied to years within the inherited Julian calendar.
Mercedonius: An intercalary month used in the pre-Julian Roman calendar. This extra month was the main device for extending the Roman year.
Republican Rome: The period of Roman history when elected magistrates and the Senate governed the state. The Republican calendar placed control of intercalation in the hands of pontiffs.

Linked from 27 pages